Fabric having heat retaining properties

ABSTRACT

Provided herein are heat retaining fabrics for articles, including articles of apparel that, among other benefits, may increase the internal body temperature of a wearer or user, including during physical activity, to facilitate detoxification of the body. Heat retaining fabric consistent with the disclosed embodiments may include a thermal insulating layer having a body-facing surface and an exterior-facing surface opposite the body-facing surface, an exterior fabric disposed on the exterior-facing surface of the thermal insulating layer, a metallic material disposed on the body-facing surface of the thermal insulating layer, and an interior fabric disposed on the body-facing surface of the thermal insulating layer. Also provided are methods of making a heat retaining fabric and articles comprising the same.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional Application No. 62/376,695, filed Aug. 18, 2016, entitled “Athletic Apparel Systems and Methods,” which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

Embodiments herein relate generally to apparel and other articles, and more specifically, to fabrics configured to increase the internal body temperature of a wearer during physical activity to provide various health benefits, including without limitation, facilitating detoxification of the body through promoting, among other things, dilation of blood and lymphatic vessels, increased perspiration, and increased blood show and triggered heat shock proteins throughout the wearer's muscles.

BACKGROUND

Activewear and sportswear apparel fabrics may include temperature-regulating technology, Such technology is typically designed to keep the internal body temperature of a wearer cool during periods of physical activity, for example during workouts and exercise. This conventional approach to activewear and sportwear design, however, does not address the various health benefits of increasing the internal body temperature of a wearer during physical activity.

SUMMARY OF INVENTION

Provided herein are heat retaining fabrics for articles, including articles of apparel that, among other benefits, may increase the internal body temperature of a wearer or user, including during physical activity, to facilitate detoxification of the body through promoting, among other things, dilation of blood and lymphatic vessels, increased perspiration, and increased blood show and triggered heat shock proteins throughout the wearer's muscles. Heat retaining fabric consistent with the disclosed embodiments may include a thermal insulating layer having a body-facing surface and an exterior-facing surface opposite the body-facing surface, an exterior fabric disposed on the exterior-facing surface of the thermal insulating layer, a metallic material disposed on the body-facing surface of the thermal insulating layer, and an interior fabric disposed on the body-facing surface of the thermal insulating layer. To increase heat retention, the apparel fabric may also include a second metallic material disposed on the body-facing surface of the thermal insulating layer and an interior fabric disposed on a body-facing surface of the second metallic material such that the second metallic material is disposed between the thermal insulating layer and the interior fabric. The thermal insulating layer may comprise neoprene (e.g., chlorophrene (CR) rubber) or any other thermal insulating material that may provide insulation against a colder or lower exterior temperature (e.g., ambient temperature). The metallic material may comprise titanium, without limitation, or any other material that may provide heat retention and/or generate heat, including during physical activity. The exterior and interior fabrics may comprise, without limitation, knit fabrics such as jersey or any other fabric that facilitates movement and/or comfort, including during physical activity. The interior and exterior fabrics may be certified and/or tested to be non-toxic for safe use in contact with the skin for example, OEKO-TEX® and/or OKO-TEX® certified and/or tested. Apparel consistent with the disclosed embodiments may comprise, without limitation, activewear, sportswear or other apparel for which heat retention is desired. Also provided, are methods of making a heat retaining article.

BRIEF DESCRIPTION OF THE DRAWINGS

The written disclosure herein describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to certain illustrative embodiments that are depicted in the figures, wherein:

FIG. 1A illustrates a simplified cross-sectional diagram of a heat retaining fabric consistent with embodiments of the present disclosure;

FIG. 1B illustrates a simplified cross-sectional diagram of the heat retaining fabric of FIG. 1A further comprising an additional thermal insulating layer consistent with embodiments of the present disclosure;

FIG. 2A illustrates a simplified cross-sectional diagram of the heat retaining fabric of FIG. 1A showing the heat retaining properties of the heat retaining fabric consistent with embodiments of the present disclosure; and

FIG. 2B illustrates a simplified cross-sectional diagram of the heat retaining fabric of FIG. 1B showing the heat retaining properties of the heat retaining fabric consistent with embodiments of the present disclosure.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

A detailed description of the embodiments of the present disclosure is provided below. While several embodiments are described, the disclosure is not limited to any one embodiment, but instead encompasses numerous alternatives, modifications, and equivalents. In addition, while numerous specific details are set forth in the following description to provide a thorough understanding of the embodiments disclosed herein, some embodiments can be practiced without some or all of these details. Moreover, for clarity, certain technical material that is known in the related art has not been described in detail to avoid unnecessarily obscuring the disclosure.

The description may use perspective-based descriptions such as up, down, back, front, top, bottom, interior, and exterior. Such descriptions are used merely to facilitate the discussion and are not intended to restrict the application of disclosed embodiments. The description may also use perspective-based terms “body-facing” (i.e., facing the body) and “exterior-facing” (i.e., facing away from the body). Such descriptions are also merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments.

The description may use the terms “embodiment” or “embodiments,” which may each refer to one or more of the same or different embodiments. The terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments, are synonymous, and are generally intended as “open” terms—e.g., the term “includes” should be interpreted as “includes but is not limited to,” the term “including” should be interpreted as “including but not limited to,” and the term “having” should be interpreted as “having at least.”

Regarding the use of any plural and/or singular terms herein, those of skill in the relevant art can translate from the plural to singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular and/or plural permutations may be expressly set forth herein for the sake of clarity.

The embodiments of the disclosure may be understood by reference to the drawings, wherein like parts may be designated by like numerals. The components of the disclosed embodiments, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the disclosure is not intended to limit the scope of the disclosure, as claimed, but is merely representative of possible embodiments of the disclosure. In addition, the steps of any method disclosed herein do not necessarily need to be executed in any specific order, or even sequentially, nor need the step be executed only once, unless otherwise specified.

Various embodiments provide heat retaining fabrics for apparel that, among other benefits, may facilitate detoxification of the body through encouraging perspiration, support the lymphatic system, and improve athleticism through principles of hyperthermic conditioning. Existing activewear or sportswear fabrics may include temperature-regulating technology to keep the internal body temperature of a wearer cool during periods of physical activity. These traditional approaches to activewear or sportwear design, however, do not address the health benefits of increasing the internal body temperature of a wearer, including during physical activity.

For example, by increasing an individual's body temperature, the wide variety of environmental toxins and chemicals that an individual is exposed to daily may be driven from the human body. These toxins and chemicals may come from antibiotics, pesticides, Bisphenol A (BPAs), polychlorinated biphenyl (PCBs), or may be introduced into the human body through absorption via the use of chemical-containing products and/or through ingestion by eating food or drinking water. Some of these toxins and chemicals may contribute to a variety of undesirable health effects including, for example, inflammation, damage to the sympathetic nervous system (SNS), weight gain, normal adrenal disruption, and other undesirable health effects.

Increasing an individual's body temperature during athletic training or other physical activities may also have benefits. For example, increasing athletic endurance, improving efficiency of transportation of oxygen to the muscles, decreasing muscle soreness and increasing muscle recovery, reducing muscle atrophy, reducing body weight or fat, reducing the body's exposure to cold temperatures, reversing the effects of hypothermia, and increasing natural hormone levels (e.g., human growth hormones and the like). Other benefits may include, promoting intermittent heating, contributing to athletic adaption, preparing muscles for elongation, and retaining fast twitch muscles for improved explosive performance activities.

Embodiments disclosed herein provide for heat retaining fabrics for apparel and other articles where body heat retention is desired. Articles consistent with the disclosed embodiments may comprise, without limitation, activewear, sportswear, outerwear (e.g., coats, parkas, jackets), top garments (e.g., tank tops, t-shirts, long sleeve shirts, hooded tops), bottom garments (e.g., shorts, capris, pants), footwear, wet suits, ski suits, swimsuits, undergarments, medical garments, socks, compression garments, and/or any combination thereof (e.g., one-piece garments). Articles consistent with the disclosed embodiments may also comprise, without limitation, other articles such as accessories, compression gear, body gear, sporting gear, support braces (e.g., back, knee, elbow, wrist), sleeping bags, headwear, gloves, scarves, and blankets.

In certain embodiments, the heat retaining fabrics disclosed herein may form part or all of an article, such as an article of clothing or apparel. For example, the heat retaining fabric may be used in one or more strategic locations of a garment. In some embodiments, the heat retaining fabric may be strategically used in areas of a garment that may encourage perspiration and/or increased body temperature by a wearer during normal or physical activity. In still other embodiments, the heat retaining fabrics may be used in areas of a garment that benefit from increased stiffness, compression, and/or lateral tension.

In further embodiments, different thickness of the heating retaining fabric may be used in different areas of a garment or other articles allowing for varied stiffness or flexibility, thermal-insulation, heat retention, compression, and/or tension based on a particular application and/or type of article. Apparel including embodiments disclosed herein may further include one or more portions strategically located to facilitate ventilation and/or air flow between a wearer's skin and the exterior of the garment e.g., certain embodiments may comprise ventilated gusseted crotches, ventilated underarm areas, and/or the like.

In some embodiments, the heating retaining fabrics disclosed herein may be configured for use in athletic apparel (e.g., sportswear, activewear, etc.) for improved fitness and athletic training. Some forms of athletic training require athletes and other individuals to reduce weight. Such training may involve, for example, lengthy sauna and/or steam room sessions, and/or the like. Apparel including the heating retaining fabrics disclosed herein may increase perspiration and reduce water weight with less physical activity and may alleviate lengthy sauna and/or steam room sessions.

In still further embodiments, the heat retaining fabrics disclosed herein may be configured for use in athletic apparel (e.g., sportswear, activewear, etc.) to increase a wearer's body temperature while performing physical activities (e.g., during athletic conditioning), referred to herein as hyperthermic conditioning. A wearer's body may adapt to associated heat stress during activity, causing increase volume of blood flow to their heart and muscles, which may be associated with a variety of benefits including, for example, increasing athletic endurance, improved efficiency of transportation of oxygen to their muscles, faster and increased muscle mass growth, reduction in muscle atrophy, and increased natural hormone levels (e.g., human growth hormone levels or the like). In further embodiments, athletic apparel including the heat retaining fabrics disclosed herein may promote, as discussed above, intermittent heating, contributing to athletic adaption, preparing a wearer's muscles for elongation, and retaining fast twitch muscles for improved explosive performance activities.

Increasing heat acclimation using embodiments disclosed herein may also improve muscle soreness and recovery, promoting the benefits of the inflammatory response. For example, physical activity while wearing apparel including the heat retaining fabrics disclosed herein may generate heat, which may increase circulation and improve nutrient delivery and waste removal in a wearer to help heal damaged tissue. Heat generation may further cause a wearer's blood vessels to dilate, facilitating improved nutritional distribution and waste removal via the wearer's lymphatic system.

Further, as discussed above, the presence of certain chemicals in the body may contribute to a variety of undesirable health effects, including weight gain. Certain chemicals present in body fat located beneath the skin may be most readily eliminated through perspiration, which may be improved by wearing apparel including heat retaining fabrics consistent with the disclosed embodiments. By increasing the internal body temperature of a wearer, the body's lymphatic system may move various waste products from cells, tissues, and organs to the liver and kidneys. The lymphatic system may, at least in part, use body movement to improve its effectiveness. Articles, including articles of clothing, including the heat retaining fabrics consistent with disclosed embodiments may facilitate improved activation of the lymphatic system, by encouraging dilation of the lymphatic vessels in response to heat generated through physical activity and associated increased perspiration.

Moreover, physical activity while wearing apparel including certain disclosed embodiments may increase heat shock proteins in the body. Heat shock proteins may be produced by cells in response to exposure to heat, and may scavenge free radicals. Furthermore, increased perspiration encouraged by apparel using disclosed embodiments may result in the secretion of dermcidin—an antimicrobial peptide—through the body's eccrine glands, reducing bacteria present on the skin and/or associated infections and acne.

A variety of thermal insulating layers may be used in connection with the heating retaining fabric disclosed herein, for example, a neoprene fabric (e.g., chlorophrene (CR) rubber) or any other material having thermal insulating properties. In certain embodiments, a neoprene fabric may be used that is relatively thin, light, and/or soft. In some embodiments, the neoprene fabric may comprise a closed-cell structure that may, among other things, increase perspiration under relatively low physical activity of a wearer and/or or reduce the likelihood of perspiration, oils, and/or other toxic or undesirable substances from being absorbed back into the wearer's skin or body. In other embodiments, the thermal insulating fabric may comprise a neoprene fabric approximately 0.3 mm to 0.5 mm in thickness. In certain embodiments, the thermal insulating layer may have relatively increased moldability, improving wearer's comfort and range of motion. In still other embodiments, the thermal insulating layer may have a higher expansion ratio than that of conventional neoprene fabric.

In some embodiments, certain surfaces of the heat retaining fabrics disclosed herein may include one or more coatings. For example, one or more coatings may be applied over a surface of a thermal insulating layer. In some embodiments, the coating may comprise a micelle structure that repels water when in contact with air and reduced surface resistance. For example, the coating may exhibit a coefficient of dynamic friction of 0.35 when dry and 0.032 when wet. The coated material may be relatively smooth to the touch, improve the ability of a wearer to put on and remove a garment, dry relatively quickly, discourage the growth of bacteria, improve the stretchability of the heat retaining fabrics, and provide for relatively high heat insulation due to low heat conduction. In addition, the low surface resistance of the coated fabric may reduce the water absorbability of the fabric and may further improve its durability and abrasion resistance.

In some embodiments, the heat retaining fabrics disclosed herein may include one or more layers comprising metallic material (e.g., titanium) that may increase thermal retention and/or generate heat via friction during physical activity. The heat retaining fabrics may also include one or more layers comprising knit fabric (e.g., nylon jersey) that may provide stretchability and/or wearer comfort, In certain embodiments, the knit fabric may be certified and/or tested to be non-toxic for safe use in contact with the skin for example, OEKO-TEX® and/or OKO-TEX® certified and/or tested.

FIGS. 1A and 1B, in accordance with various embodiments herein, illustrate simplified cross-sectional views of two examples of heat retaining fabrics, one having a thermal insulating layer comprising a body-facing surface and an exterior-facing surface opposite the body-facing surface, a metallic material disposed on the exterior-facing surface of the thermal insulating layer, an exterior fabric disposed on an exterior-facing surface the metallic material, and an interior fabric disposed on the body-facing surface of the thermal insulating layer (FIG. 1A); and the other having a thermal insulating layer comprising a body-facing surface and an exterior-facing surface opposite the body-facing surface, a metallic material disposed on the exterior-facing surface of the thermal insulating layer, an exterior fabric disposed on an exterior-facing surface of the metallic material, a second metallic material disposed on the body-facing surface of the thermal insulating layer (FIG. 1B), and an interior fabric disposed on a body-facing surface of the second metallic material layer.

As shown in FIG. 1A, the heat retaining fabric 100 may comprise one or more layers of materials with various properties. The layers may be bonded together using any suitable bonding method (e.g., lamination, heat bonding, etc.). As further shown in FIG. 1A, the heat retaining fabric 100 includes a thermal insulating layer 102 having a body-facing surface 110 and an exterior-facing surface 112 opposite the body-facing surface 110. In various embodiments, the thermal insulating layer 102 may have properties such as insulation against a lower ambient temperature (e.g., cold reflectivity and/or absorption) and/or heat direction (e.g., heat reflectively).

In some embodiments, the thermal insulating layer 102 may comprise a neoprene material (e.g., chlorophrene (CR) rubber). In some embodiments, the thermal insulting layer 102 may comprise a relatively thin neoprene fabric e.g., a neoprene fabric having a thickness of approximately 0.3 mm to 0.5 mm. In some embodiments, the thermal insulating layer 102 may comprise a closed-cell structure (e.g., a 100% closed-cell structure) that may, among other things, increase perspiration under relatively low physical activity of a wearer and/or or reduce the likelihood of perspiration, oils, and/or other toxic or undesirable substances from being absorbed back into the wearer's skin or body.

In some embodiments, the thermal insulating layer 102 may be relatively thin, light, and/or soft to facilitate physical movement within a garment that incorporates the heat retaining fabric 100—e.g., a neoprene material that is thinner, lighter, and/or softer than conventional neoprene fabrics may be used. In other embodiments, the thermal insulating layer 102 may provide a degree of stretch and/or compressibility, allowing a garment incorporating the material to have strategically designed areas of stretch and/or compression based on a particular physical activity and/or athletic pursuit. In some embodiments, the thermal insulating layer 102 may be configured to insulate heat around the body of the wearer or user.

As further shown in FIG. 1A, a metallic material 104 may be bonded to the exterior-facing surface 112 of the thermal insulating layer 102. In some embodiments, the metallic material 104 may comprise a metallic alloy layer such as a titanium alloy or the like. In some embodiments, the metallic material 104 may function as a radiant heat layer, improving the insulating properties of the fabric. For example, the metallic material 104 may reflect generated body heat towards a wearer, which may improve the retention of body heat consistent with the disclosed embodiments. The metallic material 104 may also generate friction heat through movement of the wearer or user. In certain embodiments, the metallic material 104 may comprise a 70-micron thick film of titanium alloy (although any suitable thickness may be used) under a processed coating.

An exterior fabric 108 may be bonded to an exterior-facing surface 114 of the metallic material 104. The exterior fabric 108 may comprise a knit fabric such as jersey. In some embodiments, the exterior fabric 108 may comprise a relatively low friction surface configured to facilitate easier movement while wearing a garment or other article incorporating the heat retaining fabric 100. In some embodiments, certain portions of a garment or other article incorporating the heat retaining fabric 100 may comprise different exterior fabrics. For example, high friction areas (e.g., between a wearer's legs, under a wearer's arms, etc.) may comprise a lower friction material than certain lower friction areas, The exterior fabric 108 may further provide a softer and/or otherwise more comfortable contact surface for a wearer or user.

As also shown in FIG. 1A, an interior fabric 106 may be bonded to the body-facing surface 110 of the thermal insulating material 102. The interior fabric 106 may comprise a knit fabric such as jersey. In some embodiments, the interior fabric 106 may comprise a relatively low friction surface configured to facilitate easier movement while wearing a garment or other article incorporating the heat retaining fabric 100. In some embodiments, the interior fabric 106 may be configured to, among other things, wick moisture and perspiration away from a wearer's skin, allow a garment to move more freely over a wearer's skin (e.g., which may aid in physical activity while wearing the garment and/or putting on and/or removing the garment), as well as provide a softer and/or otherwise more comfortable contact surface for a wearer or user. In some embodiments, the interior fabric 106 may be certified and/or tested to be non-toxic for safe use in contact with the skin—for example, OEKO-TEX® and/or OKO-TEX® certified and/or tested.

As shown in FIG. 1B, another metallic material 116 may be bonded to the body-facing surface 110 of the thermal insulating layer 102 of FIG. 1A, and the interior fabric 106 may be bonded to the body-facing surface 118 of the additional metallic material 116 such that the metallic material 116 is disposed between the thermal insulating layer 102 and the interior fabric 106. In some embodiments, the metallic material 116 may be the same and/or similar to the metallic material 104. The metallic material 116 may, among other things, improve the retention of body heat consistent with the disclosed embodiments.

FIGS. 2A and 2B, in accordance with various embodiments herein, illustrate simplified cross-sectional views showing the properties of the heat retaining fabrics illustrated in FIG. 1A and 1B, respectively. As shown in FIGS. 2A and 2B, the thermal insulating material 102 may reflect 200 a or absorb 200 b lower temperature radiation 200 to improve insulation of the body from a cooler exterior environment. The metallic material 104 may reflect 202 a body heat 202 toward the body to improve the retention of warm body temperature. The metallic material 104 may also generate heat 204 against the body when it moves. As shown in FIG. 2B, the additional metallic material 116 may also reflect 206 a body heat 206 toward the body to further improve the retention of warm body temperature. The metallic material 116 may also generate heat 208 against the body when it moves.

It will be appreciated that there are a variety of different configurations for the heat retaining fabrics disclosed herein. Such fabrics may include a subset of the illustrated material layers, and/or additional material layers. It will be further appreciated that the layers may be disposed in a variety of configurations. For example, more than one layer of metallic material in more than one configurations may be included in the heat retaining fabrics disclosed herein. Accordingly, it will be appreciated that the configurations illustrated in FIGS. 1 and 2 are provided for illustration and explanation only, and are not meant to be limiting.

Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the systems and methods described herein. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not limited to the details given herein, but may be modified within the scope and equivalents of the disclosed embodiments. 

What is claimed is:
 1. A heat retaining fabric comprising: a thermal insulating layer having a body-facing surface and an exterior-facing surface opposite the body-facing surface; a metallic material disposed on the exterior-facing surface of the thermal insulating layer; an exterior fabric disposed on an exterior-facing surface of the metallic material; and an interior fabric disposed on the body-facing surface of the thermal insulating layer.
 2. The heat retaining fabric of claim 1, wherein the thermal insulating layer comprises thermal insulating properties.
 3. The heat retaining fabric of claim 2, wherein the thermal insulating properties comprise reflection of ambient temperature.
 4. The heat retaining fabric of claim 2, wherein the thermal insulating properties comprise absorption of ambient temperature.
 5. The heat retaining fabric of claim 1, wherein the thermal insulating layer comprises neoprene fabric.
 6. The heat retaining fabric of claim 5, wherein the neoprene fabric is about 0.3 mm to 0.5 mm thick.
 7. The heat retaining fabric of claim 5, wherein the neoprene fabric comprises a closed-cell structure.
 8. The heat retaining fabric of claim 7, wherein the closed-cell structure comprises an 100% closed-cell structure.
 9. The heat retaining fabric of claim 1, wherein the thermal insulating layer comprises a light-weight material.
 10. The heat retaining fabric of claim 1, wherein the thermal insulating layer comprises a soft material.
 11. The heat retaining fabric of claim 1, wherein the thermal insulating layer comprises a flexible material.
 12. The heat retaining fabric of claim 1, wherein the metallic material comprises thermal retention properties.
 13. The heat retaining fabric of claim 12, wherein the thermal retention properties comprise heat retention.
 14. The heat retaining fabric of claim 1, wherein the metallic material comprises titanium.
 15. The heat retaining fabric of claim 14, wherein the titanium comprises an about 70-micro thick film of titanium alloy.
 16. The heat retaining fabric of claim 1, wherein the metallic material generates heat via friction.
 17. The heat retaining fabric of claim 1, wherein the exterior fabric comprises knit fabric.
 18. The heat retaining fabric of claim 1, wherein the exterior fabric comprises nylon jersey.
 19. The heat retaining fabric of claim 1, wherein the exterior fabric comprises stretchable properties.
 20. The heat retaining fabric of claim 1, wherein the interior fabric comprises knit fabric.
 21. The heat retaining fabric of claim 1, wherein the interior fabric comprises nylon jersey.
 22. The heat retaining fabric of claim 1, wherein the interior fabric comprises stretchable properties.
 23. The heat retaining fabric of claim 1, wherein the interior fabric is non-toxic.
 24. The heat retaining fabric of claim 1, wherein the metallic material is disposed on the exterior-facing surface of the thermal insulating layer by lamination or heat bonding.
 25. The heat retaining fabric of claim 1, wherein the exterior fabric is disposed on the exterior-facing surface of the metallic material by lamination or heat bonding.
 26. The heat retaining fabric of claim 1, wherein the interior fabric is disposed on the body-facing surface of the thermal insulating layer by lamination or heat bonding.
 27. The heat retaining fabric of claim 1, further comprising a second metallic material wherein the second metallic material is disposed on the body-facing surface of the thermal insulating layer, the interior fabric is disposed on a body-facing surface of the second metallic layer, and wherein the second metallic material is disposed between the thermal insulating layer and the interior fabric.
 28. The heat retaining fabric of claim 27, wherein the second metallic material comprises titanium.
 29. A method of making an article comprising a heating retaining fabric, the method comprising: providing thermal insulating fabric having a body-facing surface and an exterior-facing surface; disposing a metallic material on the exterior-facing surface of the thermal insulating fabric; disposing an exterior fabric on an exterior-facing surface of the metallic material; and disposing an interior fabric on the body-facing surface of the thermal insulating layer.
 30. The method of claim 29, wherein disposing the metallic material on the exterior-facing surface of the thermal insulating fabric comprises lamination or heat bonding.
 31. The method of claim 29, wherein disposing the exterior fabric on the exterior-facing surface of the metallic material comprises lamination or heat bonding.
 32. The method of claim 29, wherein disposing the interior fabric on the body-facing surface of the thermal insulating layer comprises lamination or heat bonding.
 33. The method of claim 29, further comprising testing the interior fabric for toxins.
 34. The method of claim 29, further comprising forming the article comprising the heat retaining fabric.
 35. The method of claim 34, wherein forming the article comprises forming an article of apparel.
 36. The method of claim 35, wherein forming the article of apparel comprises forming athletic apparel. 